Five Republicans are in effect are already running for president, with another 10 considering campaigns, in what party strategists describe as one of the most wide-open GOP White House races in recent memory.

While none of them have made official announcements, Republicans involved in the process say that New Jersey Gov. Chris Christie, Texas Sen. Ted Cruz, Kentucky Sen. Rand Paul and Texas Gov. Rick Perry are courting key activists and donors, making repeated visits to the early primary states and are presidential candidates who just haven’t uttered the phrase “I’m running” yet.

Cruz is expected to headquarter his campaign in Houston and Paul in Louisville. Perry spent 15 days in Iowa over the last two years, more than any of the other Republican candidates, according to the website Democracy in Action. He says he will make more stops in the early primary states before making a formal decision on his candidacy in May or June.

A fifth Republican, neurosurgeon Ben Carson, is also giving speeches and making visits to Iowa and is effectively a candidate as well. But party operatives are not sure if Carson, who has never before held elective office, is trying to build a true campaign operation to win or will use his run as a way to bring attention to himself and his causes, as businessman Herman Cain did in 2012.

In a sign of seriousness, Carson supporters have announced that they have already found a person in each of Iowa's 99 counties to serve as a chairperson for the surgeon's campaign.

And those five are far from the only ones:

Wisconsin Gov. Scott Walker, according to sources, had discussed plans to run for president if he won re-election and, now that he has, Republicans expect Walker to take more aggressive steps towards a campaign. The Bush clan is encouraging ex-Florida Gov. Jeb Bush to enter the race.

GOP sources say former Arkansas Gov. Mike Huckabee is trying to assess if he can raise enough money to be a true contender, after struggling with campaign finances during his 2008 run.

Both Florida Sen. Marco Rubio and Louisiana Gov. Bobby Jindal have laid the groundwork for entering the field as well, giving speeches at major GOP events and making multiple visits to Iowa, New Hampshire and South Carolina.

And Republicans say another bloc of potential candidates could emerge, particularly if major figures like Bush or Huckabee either don’t run or struggle on the campaign trail. This group includes Ohio Gov. John Kasich, Indiana Gov. Mike Pence, Ohio Sen. Rob Portman, Wisconsin Rep. Paul Ryan, and former Pennsylvania Sen. Rick Santorum.

Unlike in 2008 and 2012, Republicans so far say they are satisfied with this group and are unlikely to cast about for other hopefuls. The party’s flirtation with another run by Mitt Romney has ended for now, say party operatives, with Republicans ready to choose a new leader.

Party strategists say the field could include a large number of viable contenders in part because of the rise of super PAC’s. In 2012, two individuals, casino mogul Sheldon Adelson (backing Newt Gingrich) and conservative activist Foster Friess (supporting Santorum) bankrolled the opposition to Romney for months. GOP operatives say that the candidates are now in an aggressive competition to win the support of people like Adelson.

“The problem used to be, you had to raise $2,500 per person, so you had to come up with the bundlers. With Citizens United, I don’t think it’s as big of a hurdle. Now you can have somebody who gives $15 or $20 million into a super PAC and that changes the game,” said David Lane, a conservative activist who arranges private events where pastors in the early states can meet the Republican candidates.

Party operatives say the 2016 campaign will enter a new phrase now that the mid-term elections are over. For the last several months, the GOP hopefuls flew across the country to campaign for Republican congressional and gubernatorial hopefuls, in visits that served the dual purposes of helping the GOP but also raising the profiles of the likely 2016 candidates.

Now, many of the candidates may delay for a few months a formal declaration they are running for president, according to GOP strategists. Setting up a campaign headquarters and hiring a full-time staff drains dollars, and these candidates are managing to court voters and get press attention without being officially in the race.

But the 2016 contenders still in office will use their jobs to highlight conservative causes, such as Walker’s plan to sign legislation that would require people who get government benefits to pass drug tests and Cruz’s pledge to fight President Obama’s planned executive order on immigration. Kasich, in a recent interview, said he wants to ensure that at least 15 percent of the contracts given out by the Ohio state government go to minority-owned firms, his latest move in creating a kind of moderate conservatism that helped him win a landslide during his re-election bid earlier this month.

“We’ve got to pay attention to our friends in the minority community. So when you say ‘not a quota,’ I don’t know what a quota means, but there are goals,” he told influential conservative talk show host Hugh Hewitt last week. “So in the state of Ohio, there is a goal that we do 15% of all state contracts to minorities. Now maybe somebody would call that a quota. I think it’s a goal that needs to be met, because we want to make sure that every single group in the state of Ohio and in the country is optimistic and feel they are getting a fair chance.”

Huckabee this week is leading a group of pastors from Iowa, Nevada, New Hampshire and South Carolina, the states that hold the first four primary contests, on a 10-day tour that includes stops in Poland, Great Britain and the Reagan presidential library in California, where Huckabee will give a speech on Nov. 20. (The tour is designed to highlight the leadership of Pope John Paul II, Reagan, and Margaret Thatcher.)

Jindal, on January 24, is hosting a prayer event called "The Response" in Baton Rouge that will draw evangelical leaders from across the country. (Perry hosted a similar session in 2011.)

The potential candidates will also continue to visit Iowa and other early states and make appearances at events like a meeting of the Republican Governors Association next week in Boca Raton, Florida.